The famous Ring Nebula (also catalogued as Messier 57, M57 or NGC 6720) appears in the northern constellation of Lyra. It is a prominent example of a planetary nebula. This is a shell of ionized gas expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf.
Read more about Ring Nebula: History, Observation, Properties
Famous quotes containing the word ring:
“Ring out the old, ring in the new,
Ring happy bells, across the snow:
The year is going, let him go;
Ring out the false, ring in the true.”
—Alfred Tennyson (1809–1892)